1. Field of the Invention
The present invention relates to a telemeter telecontrol system, and more particularly, it relates to a telemeter telecontrol system having a master station which collects measured values from remote stations while remotely controlling operations thereof.
2. Description of the Background Art
In recent years, a telemeter telecontrol system comprising a master station and a remote station is utilized in a factory, a warehouse or the like, in order to automatically measure and remotely control meters such as gas meters and electric meters. An example of such a conventional telemeter telecontrol system is now described with reference to the drawings.
FIG. 10 is a block diagram showing the structure of a conventional telemeter telecontrol system. Referring to FIG. 10, this telemeter telecontrol system comprises a single master station 81 and a single remote station 82.
The master station 81 transmits a synchronizing signal to the remote station 82 in a constant cycle. The remote station 82, which continuously performs a receiving operation, transmits an acknowledgement signal to the master station 81 when the synchronizing signal is received from the master station 81. When the acknowledgement signal is received from the remote station 82, the master station 81 transmits data to the remote station 82.
In the aforementioned structure, however, a plurality of master stations are disadvantageously required when connection and control of a plurality of remote stations are necessary. Further, the remote station 82 disadvantageously requires high power consumption, due to the continuous receiving operation. Particularly when the remote station is battery-operated, the batteries are so quickly consumed that they must be exchanged in a short period.
Japanese Patent Laying-Open No. 5-292564 (corresponding to U.S. Pat. No. 5,446,453) discloses a transmission/receiving system for intermittently waiting for signals thereby reducing power consumption for the signal wait and increasing the battery lives. However, this transmission/receiving system is also structured to transmit data from a single transmitter to a single receiver similarly to the system shown in FIG. 10, and aimed at no transmission/receiving between a single master station and a plurality of remote stations, dissimilarly to the present invention.